In general, coated abrasive articles have abrasive particles secured to a backing. More typically, coated abrasive articles comprise a backing having two major opposed surfaces and an abrasive layer secured to one of the major surfaces. The abrasive layer is typically comprised of abrasive particles and a binder, wherein the binder serves to secure the abrasive particles to the backing.
One common type of coated abrasive article has an abrasive layer which comprises a make layer, a size layer, and abrasive particles. In making such a coated abrasive article, a make layer comprising a first binder precursor is applied to a major surface of the backing. Abrasive particles are then at least partially embedded into the make layer (e.g., by electrostatic coating), and the first binder precursor is cured (i.e., crosslinked) to secure the particles to the make layer. A size layer comprising a second binder precursor is then applied over the make layer and abrasive particles, followed by curing of the binder precursors.
Another common type of coated abrasive article comprises an abrasive layer secured to a major surface of a backing, wherein the abrasive layer is provided by applying a slurry comprised of binder precursor and abrasive particles onto a major surface of a backing, and then curing the binder precursor.
In another aspect, coated abrasive articles may further comprise a supersize layer covering the abrasive layer. The supersize layer typically includes grinding aids and/or anti-loading materials.
Optionally, backings used in coated abrasive articles may be treated with one or more applied coatings. Examples of typical backing treatments are a backsize layer (i.e., a coating on the major surface of the backing opposite the abrasive layer), a presize layer or a tie layer (i.e., a coating on the backing disposed between the abrasive layer and the backing), and/or a saturant that saturates the backing. A subsize is similar to a saturant, except that it is applied to a previously treated backing.
However, depending on the particular choice of abrasive layer and backing (treated or untreated), the abrasive layer may partially separate from the backing during abrading resulting in the release of abrasive particles. This phenomenon is known in the abrasive art as “shelling”. In most cases, shelling is undesirable because it results in a loss of performance.
In one approach, a tie layer disposed between the backing and the abrasive layer has been used to address the problem of shelling in some coated abrasive articles.
Yet, despite such advances, there remains a continuing need for new materials and methods that can reduce the problem of shelling in coated abrasive articles.